/* protoload 0.1 beta by Andreas Kalsch
 * last change: 09.07.2007
 *
 * This simple piece of code automates the creating of Ajax loading symbols.
 * The loading symbol covers an HTML element with correct position and size - example:
 * $('myElement').startWaiting() and $('myElement').stopWaiting()
 */
 
Protoload = {
    // the script to wait this amount of msecs until it shows the loading element
    timeUntilShow: 250,
	
    // opacity of loading element
    opacity: 0.8,

    // Start waiting status - show loading element
    startWaiting: function(element, className, timeUntilShow) {
        if (typeof element == 'string')
            element = document.getElementById(element);
        if (className == undefined)
            className = 'waiting';
        if (timeUntilShow == undefined)
            timeUntilShow = Protoload.timeUntilShow;
		
        element._waiting = true;
        if (!element._loading) {
            var e = document.createElement('div');
            (element.offsetParent || document.body).appendChild(element._loading = e);
            e.style.position = 'absolute';
            try {
                e.style.opacity = Protoload.opacity;
            } catch(e) {}
            try {
                e.style.MozOpacity = Protoload.opacity;
            } catch(e) {}
            try {
                e.style.filter = 'alpha(opacity='+Math.round(Protoload.opacity * 100)+')';
            } catch(e) {}
            try {
                e.style.KhtmlOpacity = Protoload.opacity;
            } catch(e) {}
			
        /*var zIndex = 0;
			if (window.UI)
				if (UI.zIndex)
					zIndex = ++UI.zIndex;
			if (!zIndex)
				zIndex = ++Protoload._zIndex;
			e.style.zIndex = zIndex;*/
        }
        element._loading.className = className;
        window.setTimeout((function() {
            if (this._waiting) {
                var left = this.offsetLeft, 
                top = this.offsetTop,
                width = this.offsetWidth,
                height = this.offsetHeight,
                l = this._loading;
					
                l.style.left = left+'px';
                l.style.top = top+'px';
                l.style.width = width+'px';
                l.style.height = height+'px';
                l.style.display = 'inline';
            }
        }).bind(element), timeUntilShow);
    },
	
    // Stop waiting status - hide loading element
    stopWaiting: function(element) {
        if (element._waiting) {
            element._waiting = false;
            element._loading.parentNode.removeChild(element._loading);
            element._loading = null;
        }
    }/*,
	
	_zIndex: 1000000*/
};

if (Prototype) {
    Element.addMethods(Protoload);
    Object.extend(Element, Protoload);
}
/* */